Electric furnace for fusing metals.



Patented Feb. 6, 1917.

3 SHEETS-SHEET I.

nv mum? //s Arm/ uns J. THOMSON.

APPLICATION FILED JAN-28,1916.

ELECTRIC FURNACE FOR FUSING METALS.

- J. THOMSON.

ELECTRIC FURNACE FOR FUSING METALS.

APPLICATION FILED JAN. 28. I9I6.

lu tented Feb.6,1917

J. THOMSON.

ELECTRIC FURNACE FOR FUSING METALS.

APPLICATLON FILED JAPLZB, 1916 Patented Feb. 6, 1917.

3SHEETSSHEET 3- m N J UNITED STATES PATENT orrIoE- JOHN THOMSON, 01? NEW YORK, N. Y., ASSIGNOR TO JOHN THOMSON PRESS COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTRIC FURNACE FOR FUSING METALS.

Specification of Letters Patent.

Patented Feb 6, 1917.

To all whom it may concern Be it known that I, JOHN THOMSON, a citizen of the United States, and a resident of Manhattan, in the city, county, and State of New York, have-invented new and useful Iinprovementsin Electric Furnaces-for F using Metals, of which'the following is aspecilication, reference being made to the accompanying drawings, forming a part hereof.

These improvements particularly pertain to furnaces adapted for fusing such metals as copper, zinc, lead, etc., and the objects hereof are to effect the named results with high thermal economy, rapidity, convenience and metallurgical efliciency.

In the drawings, which denote a preferred i embodiment of the invention,

Figure 1 is a longitudinal center section taken as on the plane indicated by line A in Fig. 2, except that the right hand lower portion thereof is taken as along the line A of said Fig. 2.

Fig. 2 is a transverse center section taken as on the plane indicated by 1; and- Fig. 3 1s a plan view, the cover of the fur nace being removed. Fig. 3 is a view taken as on the plane indicated by line C.

The furnace D is mounted upon a rocker, 4:, whereby the structure is capable of being rocked, as denoted by arrows d, e. The center of the rocker-arc should preferablybe located somewhat above the top of the furnace to insure, normally, stable equilibrium. The single rectangular chamber E contains all of the furnace elements which are inclosed by a conveniently removable cover or roof, which maybe formed of free slabs, 5, possessed of good resistanceto heat conduction.

The heating element is a suspended radiating resistor comprised in a pairofearbon plates, 6, 7 having staggered slots, as 8, forming a zig-zag electric circuit. The plates are attached to terminals, 9, 10, passing out through a wall of the furnace, but

. their inner ends are joined, whereby to be electrified in series, by a carbon connector, 12, resting upon refractory blocks, 13, 14.

Immediately above the resistor is a shallow tank, 15, in which the material to be fused is placed. This tankis'provided with a flange, 16, which-rests upon an inner course ,of the brick-work, as 17. This flange perline B in Fig.

forms the functions of sustaining the tank and alsoin cooperation with'the tank itself of completely inclosing the resistor. If the tank is formed of fragile material, or if the mposed load isexcessively heavy, one. or

more supporting pillars, as 18, may be applied. A free space is provided around the outer edge of the flange which is packed wlth cement, as 19.; the object thereof being to seal the resistor-chamber again-st the entrance of air.

One end of the tank is provided with a shallow spout, as 20, extending to the exterior of the brick-work, and beneath it is a recess, 21, having at its inner end, and contiguous to its lower surface 22, on a line with the bottom, 23, of'the tank, a tap-hole 24 which is normally closed with removable granular material, as '25.

' When the tank IS in a' horizontal position,

' the bath of melted metal will be as denoted by the broken lines 26.

In any convenient portion ofthe furnace, or as shown in Figs. 2 and 3, a block 27, is set having an axial or sloped bore, 28.

The foregoing'briefly, but it is believed adequately, describes the several elements of the furnace, whose operation will now be re-- lated.

The tank is susceptible of being very quickly and easily charged with any form of material, such as metal in pigs, slabs, or bulky scrap, by simply removing one or more of the cover-tiles.

As the inner surfaces of the sides of the tank are not in contact with the chamber- Walls, the heat from the resistor is free to act upon practically its entire surface, and V by the liberal use of heat-insulating bricks formed of the most effective material fully 85% to of the thermal energymust necessarily flow to the relatively large and cooler surface of the tank, and thence through its walls to the contained charge.

The thermal efiiciency. is all the more pro-.

nounced because of the fact that the resistorplates may be set, as shown, quite closely to the bottom of the tank.

By introducing, through the bored block, oil or zinc, as 29, inert gas or fume is produced within the resistor-chamber, consuming or displacing the air therein, hence no burning of the carbon can take place. Any hydrous vapors, or excess of gas or fume.

maybe consumed at the outer end of the block, as 30.

lVhen a bath of hot metal will have been produced, as 26, all that is necessary to effect its removal is to slightly rock the furnace and pour from the spout, 20. In practice,

a swing of from 5 to 15 as s Fig. 1, is

ample. But it is to be here particularly observed that the run-off will be from the upper portion of the bath; and also that, unless the furnace is swung to an excessive eX- tent, a portion of the fused metal will be retained, or as indicated by the broken lines, 31. It is for the removal of this pocket of metal that the tap-hole, 24:, is provided. The particular object of being able, if desired, to retain a residuum of a melt, or of a series of melts, or of a more or less continuously conducted melting operation, is to permit the precipitation, by difference of density, of a heavier metal out of a lighter;

such, for example, as lead or iron out of.

- zinc. V

of the denser metal, or metals, has been ac- Then, when a suflicient accumulation cumulatedand in: usual practice such would be much the lesser in quantitythe tap-hole is opened and it is separately evacuated. If the metal to be thus separated by density is of considerable relative volume,

then a portion of the bottom'of the tank may be depressed, to form a sump, or. the same effect can be realized by keeping the furnace slightly tilted so that the denser metal will constantly flow toward the tap.

If for any reason preferred the fused metal can be easily and quickly removed by means of ladles, that is, dipped out. So, too,

' sectional stresses are quite nominal; Whereby the thickness of wall need not be exvariability by a merely nominal input of current.

Various details may be modified without evasion of the essence of the invention; as, for example, the furnace may be tilted or swung from axial bearings instead of being rolled on a segmental arc, and the cover may be made as a monolith to be slid OH ortilted. What I claimis:

' 1. An electric metals fusing furnace provided with a chamberiwhose bottom, sides and ends are lined with refractory material; a radiating carbonresistor suspended in said chamber and an outer-lyinginclosing melt.- ing tank whose rimis in contact with the upper edges of the chamber-walls but having a free space around its sides and between its bottom and the resistor.

2. An electric metals fusing furnace having a carbon resistor suspended Within an open topped refractory chamber, an open. topped. melting tank completely inclosing the said chamber, the bottom and sides of which tank are in free space to be acted upon by directly radiated and refiectedheat emitted by said resistor and a removable cover above the tank.

3. An electric metals furnace having an open topped melting tankserving to inclose the top of a refractory chamber, a suspended carbon resistor beneath the tank and acting thereon by radiation, a pouring spout on or at one end of said tank and a rocker, upon which the furnace is mounted, the center of whose arc is located above the furnace.

This specification signed and witnessed vthis 26th day of January, A. D., 1916.

JOHN THOMSON. 

